Liquid fuel burner, atomizing type



2 Sheets-Sheet 1 March 27, 1951 F. w. OFELDT LIQUID FUEL BURNER, ATOMIZING TYPE Filed March 51, 1947 I INVENTOR. EPA A/ K E LD T March 27, 1951 F. w. OFELDT LIQUID FUEL BURNER, ATOMIZING TYPE 2 Sheets-Sheet 2 Filed March 31, 1947 IN V EN TOR. EMNK \A/OFEL 0 T 24%;; a wm Patented Mar. 27, 1951 UNITED" STAT PAT NT FF ICE 8 "Glaims1.

- This invention relates generally "to pressure: atomizing oili burners and more particularlyto: ressure atomi'zin'g burners forprod'ucing aha-methe pressure combustion of which is in theshape o'f'an annular vortex;

This; invention is an improvement of the structure disclosed in Letters Patent- No: 2989,6 75

entitled 'B'urner and issued to me on J 'uly" 1 4 194*2.

lviechanibal-ly atomizin liquid fuel" burners of trie 'annular-vortex type "can produce anunevenly distrihuted flame eventhough the jet is accu-- ra'relyplaced concentricallyof the burner because deina'ceuracies of commercial-burner:sets which produce anon-uniform conical spray pattern thereby having more fue't in the spray on one side-of the cone than on the oth'er'side: When employing burners, that have an unevenly dis tr'ibute'd flame, for'thepurpose of heating liquids passing throughc'oils, it is diflicult to obtain complete and uniform combustion and the" heattransfer to"the"'1iquid Within the'coils is inefli-- cient. Again" an unbalancedflamefrequently burns out some portion of the combustion chain her or heating coils due to the concentration of heat.

The principal object of this invention is to provide apparatus for centering the flame of a mechanical atomi'zingburnerof the annular Vorte'x type 'for' the purpose of uniformly heating a s ray solution in' a spray generator.

Another'object is to provide a novel and economical structure for' producin a forced draft tosupport combustion of atomized liquid fuel.

Another object is to provide animproved arrangement" for producing" and guiding the flame" of'an atomized'liquid' fuel burner;

Another object is'to provide animproved fire' pot orflame guiding ringwhieh act'sineonjunm thin with a'i'et' shield for producingthe desired shape and propagation of an atomizedfu-el flame;

either objects and advantages appear in the following description.

A practical embodiment illustrating the" principles of this invention is shownthe accompanyin drawing wherein:-

- Fig. 1 is a'vi'evi' invertical sectionofa portion (ifa spray generator with parts brok'ema-Way and showingtheiwi'nd box and other'burner improvementsgeomprisingthis i'nvention.

Fig." is a view" in horizontal-section of the P boX'a-nd the blower. Fig.- 3' is a perspe'ctive view of the burner assembly shown-in Fig. 1'.-

Thespray generator structure shown in the drawings is completely shown and described in application Serial No. 718,563, filed Deo embenZGi. 1946, for SprayGenerator: Thisvapor spray'generat-or is supp-lied with a solution made: up: of? :ai

chemical and a liquid such as water: which'is'i metered to a heating zone where it i's:.heated by? a metered fuel and the amount. of solution is correlated with the amount of fuel-:to': generate a:

spray mixture: of liquid and vapor'of: a liquid:

under pressure which when discharged from the;

' nozzleproduces: a spray. The character of; this spray may be varied bychangihg the=correlationu of the solution and fuel supplied tovarythe'rliq uidlcontent; orthe nozzle of the-spray" gunman be arranged to producea relatively long: spray stream ora completely'fla-shatomized spray.

In'- the particul'argenerator shown in Fig. 1i

the metered solution'i's' supp ied through the: pipe": 5 to the" lower section of the generator coils 6 which arewound' inengaugement with the sheet metal fire pot I. through the-coil'section 8 and other coil-sections; not shown; in which the spray inixtureisz gener ated andfrom whence" it travels through the pipe It to a spray gun where it is" discharged; Theheat transfer generating coils are enclosed within the casing H which is closed atthe lo'ot"-= tom and provided with a vent at the top for'the=- discharge of the product's or combustion. 'Ih'eiv generator casing H the chemical solution tank 52 and the fuel tank It are mounted in a-row-onthe top of the WindlooX In reality the wind box is the chassis of the complete generator and its width is greater than the diameter of thecasing H. As showrr in Fig. 2' a fifth wheel- [5 is pivoted to the underside of the front of the windloos: for attaching the formed plate lfi thatcarries the front wheels- E T that may be'guid'e'd'.

by'a tongue'and at theback a V-shapedp'l'ate F8? is secured to the wind box for supporting? the!- back wheel's I 9 An electric motor 23" is mounted'orr the rear" of the wind box: M and its shaft 21 extends" for wardly to carry the pulley 22 and the fan or"- blower 2 31 The-pulleyZZdrives the belt 24 is arranged toturn the pump pulley 25 thatisprovided with' a crank to" reciprocate theconnecteing rod 26 that operates positive displacement liquid solution and: fuelpumps which are arranged tosupply metered-1 quantities of-theliquid, and" fuel to thegenerator. The-liquid solution is sup plied through the pipe 5 and the-fuel i s with drawn from thetank I3 through the pipe-21 to the fuel pump where it is' -m'etered andol'e-l'i vered through the pipe-28 the alleviator 2 9; thepi pe- 30'- The solution passes -upwardly' The blower 23 is disposed within the opening 32 of the hood 33 that connects at its lower end to the closed wind box l4. The blower 23 forces air down the hood into the wind box where it flows forwardly and through the opening 34 that is disposed in axial alignment with the fire pot l and the generator casing II. A cylindrical air guide 35 defines the size of the opening 34 and extends upwardly into the fire pot Z. The upper perimetral edge of the guide 35 is turned inwardly as shown at 36 to form an annular lip to confine the air flow in close proximity to the burner jet shield 31 which is a bell-shaped member formed with a nonround tubular portion 38 that fits over the jet 3i and permits a small amount of air to pass upwardly therethrough. A plate 4!! closes the bell over the top of the jet 3| and is provided with an axial hole 4| somewhat smaller than the head of the jet. These parts of the burner are fully disclosed and described in the aforementioned patent.

The air guide'35 is mounted axially of the fir pot l and the latter is closed at the bottom except for the clearance between the inturned lip 36 and the shield 37.

The liquid fuel pipe 30 is supported by the clamping block 42 which is secured to the underside of the closure lid 43 which has a, raised central portion 44 that fits the hole 45 in the bottom of the wind box and disposed in axial alignment with the opening 34. Oppositely projecting lugs 46 are fixed to the lid 43 and are arranged to be locked under the bridge strips 4? on opposite sides of the hole 45 as shown in dotted lines in Fig. 2. Thus by using the pipe 30 as a handle the lid '43 may be inserted in place and turned ninety degrees to swing the lugs 46 under the bridge locking strips 47 and support the burner in the fire pot l. The lid 43 is provided with a longitudinally disposed slot 48 through which the pipe 30 extends together with the insulator 50 carrying the spark ignitor 51 which is held in fixed relation adjacent the shield 31 and is supplied with electrical energy by the wire 52 from a suitable spark coil. The insulator 50 is rigidly fastened to the pipe 38 by means of the clamp 53 so as to maintain the spark ignitor in fixed position relative to the burner. A plate 54 fitting around the insulator 5G and the pipe 30 and closing the open space of the slot 48 prevents air from leaking from the wind box.

- The air being driven down the hood 33 and through the rectangular box 14 would not be driven uniformly up through the guide 35 unless the bafiie members 55 and 53 are placed as shown in Figs. 1 and 2. The baffle 55 is materially wider than the bafiie 56 and they are placed on opposite sides of the longitudinal center of the wind box I4 as shown in Fig. 2 because of the rotation of the blower 23 which is counter-clockwise when viewed from the left of the drawing. The bafiie 53 is positioned further from the burner than the baffle 55 but both baflles extend to substantially the top of the wind box. With this bafiie arrangement the long rectangular wind box provides a uniform distribution of the air up through the air guide 35. If the wind box was shortened this baifie arrangement would not properly function and it has been found necessary to maintain the long wind box to obtain the proper flow of air. 1

Even though the air is uniformly discharged up through the guide 35 the jet 3| produces an unbalanced flame because of the non-uniform discharge of fuel from the burner jet 3|. Th shield trally position the flame.

4 31 deflects the air radially, creating a rolling turbulent action with the fire pot 1 to shape the burning and nonburning atomized fuel into a vortex, the axle of which is a closed curve. The fire belches up from the rolling vortex and heats the liquid solution in the coils. Owing to the fact that the cold liquid solution coil 6 engages the sheet metal fire bowl 1 the latter is prevented from burning up.

If the flame is not centered within the coils 8 the clamping screw 55 of the clamp block 42 may be loosened and the burner repositioned within the air guide 35 to properly locate the flame. The burner may be moved longitudinally of the slot 48 or the horizontal section of the pipe 30 may be rotated in either direction. Thus the nozzle may be adjusted in any direction to cen- The clamping screw on the block 42 is again tightened on the horizontal section of the pipe 30 to maintain this adjusted position. The spacing between the spark electrode 5| and the shield 31 is properly gaugedto provide a continuous spark therebetween and the slot 48 in the lid 43 is not sufficiently long to produce a shorter gap between the electrode and the air guide. This insures the proper functioning of the ignition system.

This'arrangement not only permits the flame to be properly centered within the heating coils but also permits the burner to be readily withdrawn for cleaning and inspection without disturbing the electrical and the fluid circuits which is a material advantage in this spray generator.

The upper end of the fire pot I is provided with an inwardly projecting corrugated flange 51. The top of the corrugations of this flange slopes at an angle of approximately forty-five degrees and aside from aiding to produce the vortex of the burning and unburned turbulent fuel it catches any stray dropletsfof oil and holds them" in the flame where they are burned rather than permit them to drop down on the outside of the fire pot.

The bottom 58 of the fire pot has a central;

opening 62 radially spaced from the air guide 35 and the bottom 59 of the combustion chamber is fixed to the air guide which has clearance. through the hole in the wind box-l4. A series of small holes 63 are made in the air guide at. the upper surface of the combustion chamber.

floor 59 for the purpose of permitting. any fuel that may collect inside or outside of the fire pot.

to flow to the air guide and drain through this series of holes where it is permitted to drop to the lid 43 and be retained within the upwardly.

extending annular flange 60. This stray fuel may pass from the lid through the pipe 6| to floor underneath the spray generator. In this manner the stray fuel is immediately directed; out of the machine and is not permitted to col lect or stray to other parts of the machine where it may catch on fire and burn up the machine.

I claim: V 1. In a burner structure the combination of a wind box closed at its ends, a blower arranged to force air into the wind box, a combustion chamher having a floor and mounted on top of the windbox intermediate of the ends of the latter, a fire pot mounted on the floor concentrically within the combustion chamber, an open ended air guide secured to the floor of the combustion chamber and extending from the wind box into the fire pot, means defining an opening in the bottom of the wind box in alignment with the air guide, a removable lid closing said opening;

a burner mounted on the lid and projecting up through the air guide into the fire pot and having a deflector which produces a flame in the shape of an annular vortex, and means to adjust the burner relative to the lid to center the flame within the fire pot.

2. The structure of claim 1 which also includes a pair of battles within the wind box extending the full depth of the wind box and parallel to the transverse axis thereof and positioned on opposite sides of the lid with respect to the transverse and longitudinal axes of the wind box.

3. The structure of claim 1 which also includes a bottom of the fire pot, means defining an opening in the fire pot bottom, means defining a drainage opening through the air guide to the combustion chamber adjacent the bottom thereof, said openings directing any stray fuel from the burner to the wind box, and means in the wind box to collect and discharge the stray fuel from the wind box.

4. The structure of claim 1 which also includes an ignition electrode mounted in fixed relation to the burner and adjustable therewith.

5. In a burner structure the combination of a wind box, a combustion chamber mounted on the wind box and open at its upper end, a fire pot mounted within the combustion chamber, an open ended air guide extending from the wind box into the fire pot, means defining an opening in the bottom of the wind box aligned with the air guide, a lid to cover the opening, a burner supported on the lid and extending into the fire pot through the air guide, a clamp on the lid for supporting the burner thereon, and radially adjustable means on the lid whereby the burner may be adjusted radially of the fire pot to center the flame therein when the clamp is loosened.

6. In a burner structure, the combination of an enclosed combustion chamber vented for the discharge of products of combustion, a tubular fire pot open at one end and mounted in the combustion chamber, an open ended tubular air guide extending concentrically into the fire pot for directing an air blast thereinto, a fuel line extending into the air guide, an atomizing fuel burner nozzle on the end of the fuel line, a bell deflector mounted on the nozzle, and an inturned flange fire pot open at one end and mounted in the combustion chamber, an open ended tubular air guide extending concentrically into the fire pot for directing an air blast thereinto, a fuel line extending into the air guide, an atomizing fuel burner nozzle on the end of the fuel line, a bell deflector mounted on the nozzle, an inturned flange around the opening of the fire pot, and an inturned flange on the end of the air guide, the bell deflector being spaced slightly from the pipe and nozzle to cooperate with the flange on the air guide and the flange on the fire pot to produce an annular vortex of air and atomized fuel that extends from the bell deflector to the flange on the fire pot and permits the stray droplets of atomized fuel to impinge on the inturned flange of the fire pot.

8. In a burner structure, the combination of a wind box, a combustion chamber mounted on the wind box and open at its upper end, a fire pot mounted within the combusion chamber, an inturned annular corrugated flange 0n the upper end of the fire pot, an open-ended air guide extending from the wind box into the fire pot, means defining an opening in the bottom of the wind box aligned with the air guide, a lid to cover the opening, a burner supported on the lid and extending into the fire pot through the air guide, means on the lid for supporting the burner, and radially adjustable means on the lid whereby the burner may be adjusted radially of the fire pot to center the flame therein and permit the stray droplets of atomized fuel to impinge on the inturned corrugated flange.

FRANK W. OFELDT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

